Lead-press



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UNITED STATES PATENT OFFICE.

HENRY B. COBB, OF WILMINGTON, DELAVARE.

LEAD-PRESS.

SPECIFICATION forming part of Letters Patent No. 408,875, dated August6, 1889.

Application iiled October 5, 1888.

To @ZZ whom, t may concern.-

Be it known that I, HENRY B. COBB, a citi- Zen of the United States,residing at Vilmington, in the county of New Castle and State ofDelaware, have invented a new and useful Improvement in Lead-Presses, ofwhich the following is a specification.

My invention relates to an improvement in the class of devices commonlyemployed to make tubing, particularly from molten lead, and involving asgeneral features a massive frame supporting a stationary plunger, and areciprocating ram below the plunger and carrying, to reciprocate withit, a mold comprising a core tube, and a die-tube transverse to theplunger and lead-cylinder and leading into a chamber and snrmounted by aleadcylinder communicating with the mold, and in vertical line with theplunger, whereby when the ram is forced upward it presses the Y contentsof the lead-cylinder against the plunger, which thus enters the cylinderand forces the lead laterally through the mold, thereby forming it intotubing, which emerges from the machine at a right angle to the latter.

The immediate object of my invention. is to improve a machine involvingthe general construction above set forth in a manner to adapt itparticularly to coat with metal any length (up to many hundreds of feet,if desired) of tubing composed of plastic or incompact material, such assoft rubber.

In order to render the machine suitable for my purpose the mold shouldbe stationary, since the tubing to be coated being incompact, like softputty, if the mold were reciprocating in feeding the tubing the latterwould be liable to break. Other changes besides are desirableparticularly to adapt the said machine to my purpose, and will bedeiinitely pointed out in the description and claims hereinaftercontained.

In the accompanying drawings, Figure l shows a lead-press in sectionalelevation; Fig. 2 is a broken sectional View of a modified constructionof the die detail, and Fig. 3 is a broken end view showing the upperpart of the lead-press.

A is the lead-press, having metal columns T, supported on a suitablebase (not shown) and surmounted by a metal block r. Below Serial No.287,270. (No model.)

the block a" and secured to or integral with it is a head r2.

B is a metal block havinga chamber gin one side and semi-cylindricalchannels p and o in the same side and leading from opposite directionsinto the chamber q, and around the chamber q is formed in the block Bthe usual horizontal chamber n for steam.

B is another block having a chamber q in one side and semi-cylindricalchannels p and o', leading from opposite directions and, like thechannels p and o, from the outer lateral sides of the block into thechamber q', and the usual steam-chamb er n is provided around thechamber q. A hollow plunger C extends from the side of the block Bopposite that in which the chamber q is provided, the pas sage m in theplunger being preferably cylindrical and extending through it into thesaid chamber. The parts B and B are se cured to the under side of thehead r2 and to each other in a manner to cause the chambers q and q andthe channels p p and o o to coincide, as shown. The upper end of thepassage m in the plunger is covered by a bridge m', (which may be castintegral with the block B having openings m2, preferably four in numberand equidistantv apart, between the edge of the bridge and edge of themouth of the passage m, the openings affording communication between theplun gerepassage and chamber q q.

D is a core-tube tapering toward one end to the extremity thereof on itsouter :side and tapering on the inside part way only toward the end andcylindrical the rest of the way, as shown.

E is a die-tube, preferably concave at one end, as shown, and having abore resembling that in the tube D. The tubes D and E are inserted intothe passage afforded by the coincident channels o o and p p',respectively, from opposite ends thereof, and meet at their respectivetapering and concave extremities 'near the center of the chamber q q',the tube D thus entering the concave end of the tube E. and the bores inboth tubes coinciding. The tubes are not suficiently long to extend tothe outer extremities of the passages provided to receive them, therebyleaving sufficient space behind each (and which is thread- IOO ed, asshown) to receive hollow externallythreaded plugs D and E', which shouldflare, as shown, at their outer ends.

F is a ram, of ordinary construction in machines of the class to whichmy improvement relates, and operated', preferably, by hydraulicpressure, (to effect which operation the means are not, however, shown,inasmuch as they involve no feature of novelty and are common for thepurpose and G is the lead-cylinder, the inside bottom as of which shouldbe s-ynclinal, and in the wall of the cylinder is the usualcircumferential passage l for steam. rlhe cylinder G is supported on theverticallyreciprocating ram F in a position wherein the plunger@coincides with the chamber portion t-hereof. y

To operate the machine, a charge of molten lead (this being thesubstance I employ, though of course the operation remains the samewhatever be the substance, so long as the latter be suitable for thepurpose) is introduced into the cylinder G and allowed to set for a fewminutes, when the ram is actuated to raise the lead-cylinder and causethe plunger C to enter it. As the plunger (which fits snugly into thelead-cylinder) comes into contact with the surface of molten lead, the

air on the surface of the latter will have been forced out through thepassage m. The pressure of the plunger against the lead in the cylinderG forces the lead into the chamber q q', and thence laterally around thetapering end of the tube D into the tube E, thereby forming it intotubing, in which form it emerges from the machine at the plug' E', whenit is led into a trough H, through which cold water is caused to How,and thus cooled to permit it to be handled for coiling it upon asuitable reel. (Not shown.) Soon after the metal has been started aroundthe cylindrical end of the tube D, I insert an end and feed a length ofplastic tubing I (through which water or other suitable fluid isrunning, as described in my application for Letters Patent, Serial No.287,269, filed concurrently herewith) through the tube D D into the tubeE, whereby it becomes coated with the lead as the latter is formed intotubing, and the pressure of the lead forces the coated plastic tubingout of the machine, as described. When the charge of lead in thecylinder is exhausted in the operation, as described, the cylinderrequires replenishing to enable the operation to be repeated orcontinued, the former when the charge has been just sufficient to coatthe length of tubing to be incased, and the latter when the charge isinsufficient to coat the entire length, which maybe so great as toproduce repeated emptying of the lead-cylinder, and consequently requirerepeated replenishing thereof. When the plunger C reaches nearly to thebottom of the cylinder G, it compresses the remnant of the contents ofthe cylinder into the form of the bottom of the latter against the endof the plunger, as shown by the dotted lines at sage m, the cylinder isentirely depleted of its contents by withdrawing from the plunger, andwhen, after replenishing the cylinder, it is again raised for anotheroperation, or to continue the operation, the plunger forces outlaterally, owing to its form, all air in the cylinder above the lead,and thus prevents any air from becoming mixed with the molten metal,which would tend to produce flaws in the tubing'.

If the plastictubing I be passed through the machine without stoppage,there is no danger of its being burned by the heat of the metal broughtinto contact with it, even if it contain no water or other coolingmedium, (the purpose of introducing water through the plastic tubingbeing' set forth in my aforesaid concurrent application for a method ofincasing tubing composed of plastic material.) If stopped, however, theexternal surface of the plastic tubing through which water is passing,as aforesaid, may become inj ured by the heat to which it would besubjected during the period of stoppage in the chamberq q. To guardagainst injury from this cause, I construct the tubes D and E as shownin Fig. 2, and a description of which construction is as follows:

Each tube D and E has its bore enlarged, and contains centrally a metal(preferably brass) tube 7L, around which is packed magnesia g, or othermaterial non-conductive of heat. 'lhe inner end of each tube h enters asocketas shown, in the forward inner end of its respectiveinclosing-tubeD and E, and may be withdrawn therefrom by sliding itslightly backward, if desired, when a stoppage of the feed of theplastic tubing is made, in order to withdraw it entirely into thenon-conducting material and thus reduce the exposure of its end to theinfluence of the heat in the chamber q q', through which end, if thusexposed, the heat would be the more readily conducted to the plastictubing'.

Vhat I claim as new, and desire to secure by Letters Patent, is

l. In a lead-press, the combination of a reciprocating lead-cylinder, astationary hollow plunger in line with and above the lead-cylinder, anda stationary mold above the plunger and communicating therewith,substantially as described.

2. In a lead-press, the combination of a reciprocating lead-cylinderhaving a synclinal bot-tom, a stationary hollow plunger in line with andabove the lead-cylinder, and a stationary mold above the plunger andcommunicatin g therewith, substantially as described.

3. In a lead-press, the combination of a reciprocating lead-cylinder G,a stationary hollow plunger C in line with and above the lead-cylinder,a stationary chamberq q above the hollow plunger and lcommunicatingtherewith, tubes D and E, leadinghorizontally into IOO IIO

the sides of the said chamber and coinciding at their bores near thecenter thereof, the tube D extending into the adjacent end of the tubeE, and a bridge m in the chamber q q over the openingin the plunger,substantially as described.

Il. In a lead-press, the combination of a reciprocating lead-cylinder G,a stationary hollow plunger C in line with and above the leadcylinder, astationary chamber q q above the hollow plunger and communicatingtherewith, tubes D and E, containing` each a tube 7 1., surrounded bymaterial g non-conductive of heat and leadinghorizontally into the sidesof the said chamber and coinciding at their bores near the centerthereof, the tube D cX- tending into the adjacent feed of the tube E,and a bridge m in the chaniber q q over the opening` in the plunger,substantially as described.

5. In a lead-press, the combination of a reciprocating lead-cylinder G,having a synclinal bottom, a stationary hollow plunger C in line Withand above the lead-cylinder, a stationary chamber q q above the hollowplunger and communicating therewith, tubes D and E, containing each atube 71 surrounded by material g non-conductive of heat and leadinghorizontally into the sides of the said chamber and coinciding at theirbores near the center thereof, the tube D extending into the adjacentend of the tube E, and a bridge m in the chamber q q over the opening inthe plunger, substantially as described.

HENRY B. COBB.

In presence of M. J. BOWERS, J. W. DYRENroRri-r.

